1. Technical Field
This invention relates to coolant control valves for rolling mills that are used for the reduction of metals and require coolant to be supplied during use.
2. Description of the Prior Art
Prior art devices of this type have generally relied on a plurality of remotely positioned pilot control valves requiring a large number of inter-connecting controlled conduits extending from the pilot valves to the coolant control valves at the point of us. Prior art patents relating to pilot operated control valves include U.S. Pat. Nos. 3,145,967, 3,159,374, 4,391,296, 3,880,358, 4,360,037, 4,387,739, 4,247,047 and applicant's U.S. Pat. No. 4,568,026.
In U.S. Pat. No. 3,145,967 an elastic sleeve is arranged in relation to a core positioned in a fluid passageway and by the introduction of air pressure will distort the plastic sleeve inwardly against the core closing the fluid passageway. The air pressure is controlled by a solenoid operated valve.
In U.S. Pat. No. 3,159,374 a flexible diaphragm is arranged to intercept a fluid passageway through the valve when fluid pressure is applied to one side of the diaphragm to distort same, closing the passageway. The fluid pressure for operating the diaphragm is controlled by a solenoid valve.
In U.S. Pat. No. 4,391,296 a valve having a valve plug which moves in and out of closing relation respect to a fluid passageway between an inlet and an outlet port is shown wherein the valve plug is urged closed by a spring and moved to open position by a solenoid.
In U.S. Pat. No. 3,880,358 a coolant control valve is disclosed which utilizes a spring urged valve element for closed position and a control fluid, such as air, to urge the valve element to open position.
In U.S. Pat. No. 4,360,037 a self-cleaning filter assembly for a solenoid actuated valve is disclosed which uses fluid pressure to operate a diaphragm to control the opening and closing of the valve.
In U.S. Pat. No. 4,387,739 a valve module for a digital coolant control system is disclosed which utilizes a solenoid urged valve element with a spring return to control the fluid coolant through the passageway defined.
In U.S. Pat. No. 4,247,047 a zoned digital coolant system is disclosed which shows a plurality of valves in a multiple manifold configuration with each of the valve elements being activated by a solenoid and spring return for the supply of coolant to a spray nozzle.
Finally, in applicant's U.S. Pat. No. 4,568,026 a pilot operated coolant control valve in a manifold assembly is disclosed which defines the combination of a cartridge valve system having a spring urged valve element for control of coolant to a spray nozzle activated by an encased adjacent pilot control valve which is activated by a solenoid and spring return. The patent allows for multiple positioning of easily replaced cartridge valve assemblies within a multiple manifold configuration including the electrical connections in a totally enclosed environment.
Applicant's present invention allows for positioning point of use control of coolant valves reducing the cost and complexity of installation and repair time normally required due to the length of the pilot air supply lines from the pilot valves which are normally remotely located to the coolant control valves as normally found in standard rolling mill environments.